The present invention relates generally to a mixer for mixing viscous fluids, and more particularly, to a mixer configured for attachment to a power tool for mixing viscous construction materials.
Mixers that are attachable to power tools for mixing viscous construction materials, such as cement and wallboard compound, are known. Conventional mixers typically have a shaft that is attachable to a power tool, such as a drill, and paddles that extend radially from the shaft. When the power tool is activated, the paddles rotate about the axis of the shaft to mix the viscous material.
Users of conventional mixers, such as drywall or wallboard finishers, use the mixer to stir or agitate wallboard joint compound before it is applied to the wallboard. Joint compound is a highly viscous fluid that is typically mixed at high mixer rotational velocities to have a thinner and smoother consistency so that it can be applied evenly. In many cases, water must be added to the joint compound to thin the mix, as well as to help the paddles of the mixer move through and fold the viscous material.
Conventional mixers have several disadvantages. Instead of achieving the desired radial and axial mixing of the viscous material, conventional mixers tend to only mix the viscous material radially relative to the mixer. Often times, when conventional mixers are held stationary, the added water is not folded into the material but instead stands on top of the material. To achieve a desired consistency, the user must manipulate the drill and displace the shaft at least in the axial direction. Further, achieving the desired consistency is inefficient with conventional mixers because a large amount of time is required to achieve the desired mixing of the material. Another disadvantage of conventional mixers is that there is significant operational vibration. When the paddles do not move evenly through the viscous material, the mixer and the container holding the viscous material vibrate. To prevent or lessen the vibration of the container, the user will often use their legs or feet to stabilize the container, often assuming an awkward or uncomfortable stance.
Also, the vibration of conventional mixers and of the container causes splattering of the material, and/or any standing water on top of the material. Thus, the user must use caution to prevent the splatter from landing on the work area. This condition is exacerbated when users run the mixers at higher speeds in rush situations.
A further problem with conventional mixers is that the relatively sharp-edged peripheral edges of the paddles operating at high speeds will contact the sides or bottom portions of the container, typically 5-gallon plastic pails, and “shave off” portions of the container, which contaminates the material. Further, such contact may cause the drill and mixer to jump back in the user's hands, disrupting the mixing operation.
Thus, there is a need for an improved mixer that more evenly mixes the viscous material.
There is also a need for an improved mixer with reduced vibration and splatter during use.
There is a further need for an improved mixer that reduces the amount of container-origin contaminants in the viscous material.